Question 2 - Normal Distribution

The time needed to complete a final examination in a particular college course is normally distributed with a mean of 160 minutes and a standard deviation of 25 minutes. Answer the following questions:

a.What is the probability of completing the exam in 120 minutes or less?

b.What is the probability that a student will complete the exam in more than 120 minutes but less than 150 minutes?

c.What is the probability that a student will complete the exam in more than 100 minutes but less than 170 minutes?

d.Assume that the class has 120 students and that the examination period is 180 minutes in length. How many students do you expect will be unable to complete the examination in the allotted time?

Question 3 - Sampling Distribution

The Economics Policy Institute periodically issues reports on wages of entry-level workers. The Institute reported that entry-level wages for male college graduates were $43.36 per hour, and for female college graduates were $37.60 per hour. Assume the standard deviation for male graduates is $2.50 and for female graduates is $2.10

a.What is the probability that a sample of 50 male graduates will provide a sample mean within $0.50 of the population mean, $43.36?

b.What is the probability that a sample of 50 female graduates will provide a sample mean within $0.50 of the population mean, $37.60?

c.In which of the preceding two cases, part (a) or part (b), do we have a higher probability of obtaining a sample estimate within $0.50 of the population mean? Why? (

d.What is the probability that a sample of 120 female graduates will provide a sample mean more than $0.30 below the population mean?